共查询到20条相似文献,搜索用时 78 毫秒
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气相色谱-质谱法分析罗勒中挥发油的化学成分 总被引:2,自引:0,他引:2
利用水蒸气蒸馏法提取维吾尔药材罗勒中的挥发油成分,并用气相色谱-质谱法分析其化学成分,共鉴定出63种化学成分,占挥发性物质含量的87.49%.在罗勒挥发油中主要化学成分为a-萜品油烯(30.97%),香榧烯醇(20.57%),a-萜品油(6.87%),β-月桂烯(4.75%).δ-愈创水烯(3.19%),杜松烯(3.16%)等. 相似文献
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应用声表面波气相色谱快速定性分析姜黄挥发油。声表面波气相色谱采用DB-5毛细管色谱柱,初始温度45℃,6℃/s程序升温至160℃,检测结果与气相色谱质谱结果进行比较。姜黄挥发油定性分析中, 声表面波气相色谱20s完成检测,而气相色谱-质谱需要30min完成,声表面波气相色谱检测更高效;同时,声表面波气相色谱与气相色谱质谱共同检测出姜黄挥发油中10种化学成分,且10种化学成分相对百分含量总和占挥发油总成分的90%以上,由于色谱柱长度区别,声表面波气相色谱检出的化学成分相对较少;定量分析中,对声表面波气相色谱进样方式进行了考察,顶空进样与液体进样对化学成分相对百分含量检测有较大差异;采用与气相色谱质谱一致的液体进样方式,对姜黄挥发油中反式石竹烯定量分析,声表面波气相色谱最低检出限可以达到16.9 pg,在0.001624~0.01624 mg/mL范围内R=0.9976具有较好的线性关系,且精密度和重复性较好。声表面波气相色谱能够用于姜黄挥发油的快速定性和定量分析,为中药挥发油的分析提供了新的快捷的检测技术基础。 相似文献
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海南主要地域生咖啡豆挥发性化学成分对比研究 总被引:2,自引:0,他引:2
采用固相微萃取-气相色谱-质谱法(SPME-GC-MS)分析海南万宁地区咖啡豆和澄迈地区咖啡豆中挥发性化学组分,通过谱库检索、保留指数对化合物定性,比较两种咖啡豆之间差异。实验结果表明:万宁地区咖啡检出化合物种类91种,澄迈地区咖啡检出106种化合物,有66种相同的化合物,相同组分为75.52%。相同化合物中万宁地区咖啡占总含量的89.86%,澄迈地区咖啡占总含量的85.70%。 相似文献
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混合三烷基氧膦组成和性能的研究 总被引:1,自引:0,他引:1
用气相色谱和质谱法研究了7种不同产地的混合三烷基氧膦的组成,测试了其水洗液的pH值,在水和酸中的溶解率及温度与出现第二有机相的关系。这些数据对于该试剂用于溶剂萃取过程有参考价值。 相似文献
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Results of radionuclide activity concentration measurements in deposition and ground-level air conducted at the station of
the Institute of Physics situated 3.5 km from the Ignalina Nuclear Power Plant (Ignalina NPP) in 2005 are analyzed. Atmospheric
depositional fluxes of 7Be, 60Co and 137Cs are estimated. Radionuclide particle deposition rates are calculated. The Hybrid Single-Particle Lagrangian Integrated
Trajectory (HYSPLIT) model of the global dispersion and deposition is used to explain variations in the 137Cs activity concentration in the ground-level air in the Ignalina NPP region in 2005. An increase in the 137Cs activity concentration of up to 17.4 μBq m−3 on 30 October-5 November is studied. Modelling results show that the Chernobyl NPP Unit 4 Sarcophagus and the radiocaesium
resuspension from the Chernobyl NPP accident polluted regions are sources of 137Cs to the environment of the Ignalina NPP. Results on solubility in water of aerosols — carriers of 137Cs — are discussed. 相似文献
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A. Ghosh S.K. Adhikari 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,2(1):31-36
The solutions of a renormalized BCS equation are studied in three space dimensions in s, p and d waves for finite-range separable
potentials in the weak to medium coupling region. In the weak-coupling limit, the present BCS model yields a small coherence
length and a large critical temperature, , appropriate for some high- materials. The BCS gap, , and specific heat as a function of zero-temperature condensation energy are found to exhibit potential-independent universal scalings. The
entropy, specific heat, spin susceptibility and penetration depth as a function of temperature exhibit universal scaling below
in p and d waves.
Received: 18 July 1997 / Revised: 8 September 1997 / Accepted: 29 September 1997 相似文献
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The concepts of uncertainty in prediction and inference are introduced and illustrated using the diffraction of light as an example. The close relationship between the concepts of uncertainty in inference and resolving power is noted. A general quantitative measure of uncertainty in inference can be obtained by means of the so-called statistical distance between probability distributions. When applied to quantum mechanics, this distance leads to a measure of the distinguishability of quantum states, which essentially is the absolute value of the matrix element between the states. The importance of this result to the quantum mechanical uncertainty principle is noted. The second part of the paper provides a derivation of the statistical distance on the basis of the so-called method of support. 相似文献
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We present the action and transformation laws of supergravity in 11 dimensions which is expected to be closely related to the O(8) theory in 4 dimensions after dimensional reduction. 相似文献
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In this paper, we investigate the data of industries in China and find that the frequency distributions of fixed assets and fixed-assets’ investment of industries obey power laws. We show that these power-law modes can be explained by the rules of the Simon Model, rather than the existing investment theories such as the classical investment theory or acceleration principle. Moreover, the mechanism of the investment distribution may be similar to the forest-fire model of self-organizing criticality. By introducing the complex system methods, this research changes the traditional opinion of the investment and gains some meaningful understanding in the dynamics of industries and the economic cycle. 相似文献
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I. N. Wischnewski H. V. Klapdor H. Fromm P. Herges 《Zeitschrift für Physik A Hadrons and Nuclei》1981,301(1):29-34
High spin states have been investigated by the reaction90Zr(19F, 3nγ), using an Anticompton spectrometer device, for the nucleus106In, for which no in-beamγ-spectroscopic information was available up to now. A level scheme has been constructed up to anI =(13,14) state. 相似文献
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It is shown that bulk semiconductors exhibit strongly asymmetric Fano-type resonance profiles in magnetoabsorption processes
involving the formation of hot electron-hole pairs (EHPs) and accompanied by the scattering of the EHPs by defects. This result
is valid for transitions to electronic states with large Landau quantum numbers, when the Coulomb interaction plays a small
role. The physical reason for such a sharp change in the magnetoabsorption coefficient as compared with the expected result
for the ordinary density of states in a quantizing magnetic field is that the electronic excitations are quasi-one-dimensional.
The form of the resonance absorption is in good qualitative agreement with the experimental data.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 8, 619–622 (25 April 1996) 相似文献